constantly urinating, now feet swelling...

this only started a month ago,his not been unwell and is quiet fit.it started by him constantly urinating which made him tied as he had to go to the toilet very often even during the night,we took him to the doctors who said he had high blood pressure and kidney infection and he was given medication for that.he then felt abit better but mid last week his feet started swelling and we put it down to the very hot weather here 28-30 degress,but then the urinating started again,his blood pressure is higher and he could not pass stool for a week,went back to the doctors,did blood test,but they say its all fine and put it down to the high blood pressure,but it still doesn,t seem ok.